Refer to the exhibit. Router 1 is a core ABR in a Cisco Unified MPLS environment. All of the router 1 BGP peers are established, but traffic between customers is failing. Which BGP configuration…

Question

Exhibit

Options

• AIt must be configured for graceful restart
• BIt must be configured with a route reflector
• CIt must be configured with send labels
• DIt must be configured with PIC edge

• A
  2% (1)
• B
  11% (6)
• C
  82% (46)
• D
  5% (3)

Explanation

Cisco Unified MPLS (also called Seamless MPLS) stitches end-to-end LSPs across multiple IGP domains using BGP as the label distribution protocol between domains. For this to work, BGP peers must advertise MPLS labels along with prefixes-this is accomplished with the 'send-label' (or 'send-community' with label allocation) configuration on the BGP neighbor. Without 'send labels', BGP will exchange prefixes but will not carry the MPLS label bindings needed to build a continuous LSP across domain boundaries, which explains why traffic fails even though all BGP sessions are established. Graceful restart (A) addresses control-plane failover, not label propagation. A route reflector (B) aids iBGP scalability but does not fix missing label signaling. PIC edge (D) is a fast-reroute feature unrelated to this issue.

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